This application claims the priority of prior application 197 09 601.8 filed in Germany on Mar. 8, 1997, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a plate-type heat exchanger, particularly an oil/coolant cooler, which comprises several plates which are arranged in parallel to one another and which form respective hollow chambers between one another which are provided with corrugated metal turbulence sheets for increasing the heat transfer and through which one of the respective media which participate in the heat transfer flows in an alternating manner.
A plate-type heat exchanger of this type is known from European Patent Document EP 06 23 798 A2, where trough-shaped heat exchanger plates were provided whose surrounding edges are placed against one another when the heat exchanger plates are stacked upon one another and which can then be tightly soldered to one another to form hollow chambers. In this case, each of the turbulence inserts inserted between the heat exchanger plates consists in a conventional manner of a thin metal sheet, preferably an aluminum sheet, which, in a rolling and cutting operation, was provided with a plurality of corrugations which are situated side-by-side and behind one another and which, viewed in the rolling direction, are arranged in different rows or are offset with respect to one another. These inserts are used for increasing the heat transfer capacity. However, when they are inserted between the inflow and outflow opening in their rolling direction or transversely to the rolling direction, they impair the pressure drop and the distribution of the media.
It is an object of the invention to construct a plate-type heat exchanger of the initially mentioned type such that a more uniform flow of the heat transfer media through the hollow chambers is achieved even when the metal turbulence sheets used for increasing the heat transfer are inserted.
For achieving this object, it is provided in the case of a plate-type heat exchanger of the initially mentioned type to divide the metal turbulence sheets into sections in which a different alignment exists of the course of the corrugations.
As a result of this measure, the flow can encounter different flow resistances in sections and it becomes possible in this manner to achieve an also largely uniform distribution of the heat transfer media in the individual hollow chambers despite the arrangement of the metal turbulence sheets. Deflection installations in the chambers through which the flow is forced may be eliminated. This also eliminates the expenditures for arranging such deflection walls inside the hollow chambers.
As a further development of the invention, in the case of turbulence metal sheets which were produced by rolling in the initially described manner, the desired alignment with respect to the rolling direction can simply be selected differently, and it was found to be particularly simple for the rolling direction in the sections to be in each case rotated by 90.degree. with respect to that of the adjacent sections. Viewed from the inflow and outflow openings of the hollow chambers, this will result in sections with higher flow resistances and those with lower flow resistances, and the sections can be placed and designed such that the flowing medium is forced by the flow resistances to flow through the whole space of the hollow chamber in a flow which is as uniform as possible.
As a further development of the invention, the sections can be set off with respect to one another by separating cuts which may, for example, have defined contours or may be straight separating cuts. In a particularly simple manner, three sections can be formed by two diagonal cuts which are arranged mirror-symmetrically with respect to a transverse center plane which is symmetrically situated between the assigned inflow and outflow openings of the hollow chamber such that two outer sections, which have one inflow or outflow opening respectively, and an approximately trapezoidal center section are created.
As a further development of the invention, the diagonal sections can be arranged to be sloped at an angle of 30.degree. with respect to the transverse center plane. In this case, the respective inflow or outflow opening is placed in the narrower area of the assigned outer section. In this embodiment, three different parts of the metal turbulence sheets respectively can then be placed in the hollow chambers.